Device and method for treatment with magnetic fields

ABSTRACT

The invention relates to a device for treatment with magnetic fields, which provides an easily transportable and storable device for the treatment with magnetic fields, which is also convenient for patients and in particular is economical to produce. The device comprises: a first device for generation of a first magnetic field, a second device for generation of a second magnetic field and a support with an upper side and a lower side, whereby the support is embodied for applying the treated body regions of the patient thereto.

This application claims priority in PCT International Application No.PCT/EP02/05967, filed May 31, 2002, and German Application No. DE 201 09058.9 filed on May 31, 2001, the disclosures of which are incorporatedherein by reference.

FIELD OF THE INVENTION

The invention relates to an apparatus and a method for treatment withmagnetic fields in general, and to the influencing of spins and/ormagnetic moments in tissue to be treated, in particular.

BACKGROUND OF THE INVENTION

Non-invasive treatment methods are finding ever more new fields ofapplication in the medicine. With respect to the invention registeredhere, apparatuses and methods for therapeutic treatment by means ofexternal magnetic fields should be mentioned in particular. Even though,until now, the precise mechanism of operation of such therapies has notbeen understood in detail, their therapeutic success has beenscientifically proven and is generally recognized. Investigations intothe results of known magnetic field therapies can be found, for example,in “Orthapādische Praxis” August/2000, [Orthopedic practice] year 36,pages 510 to 515 and in Fritz Lechner, “Elektrostimulation undMagnetfeld-therapie. Anwendung, Ergebnisse und Qualitātssicherung” 1989[“Electrostimulation and magnetic field therapy. Use, results andquality assurance”].

In particular, it has been found in investigations such as these thatmagnetic field therapies applied to patients in some cases produceconsiderable improvements in the signs and symptoms without significantnegative side effects that can be verified. A further major advantage ofmagnetic field therapies is that an operation which is associated withconsiderable pain, risks and costs for the patient may possibly becompletely avoided.

By way of example, DE 40 26 173 discloses an apparatus which producespulsed and modulated magnetic fields in order to treat patients. In thiscase, body tissue is subjected to a magnetic field which is produced bysuperimposition of a constant magnetic field and a magnetic alternatingfield.

Pulsed magnetic fields are typically produced by means of a pulsedcurrent, which flows through a coil. However, pulsed fields such asthese in coils require a large amount of energy and have a high degreeof inertia since the coil inductance slows down the rate of change ofthe field.

The healing effect of this magnetic field therapy comprises, inter alia,the relief of osteoporosis and the consequences of a stroke. In this, itappears to be probable that the magnetic fields which are appliedpromote transport and/or metabolism processes which lead to a positivetherapeutic effect. Until now, it has been assumed that the positivetherapeutic effect is caused by an energy interchange between fields andcomponents of cells (protons, ions etc.). In this case, the energytransfer has been explained by the stimulation and/or absorption ofion-cyclotron resonances (ICR) in a biological body, and appropriate,ICR conditions are thus looked for. The known apparatuses areconsequently based on production of ICR conditions.

However, this causal explanation appears to be questionable in somecircumstances, since cyclotron resonances generally occur only on freeparticles, for example in a vacuum or in the case of electrons in theconductance band of a semiconductor. Furthermore, simple calculation canalso be used to show that a cyclotron movement will be carried out on anorbit whose radius is intrinsically greater than the average diameter ofa cross section of a human body. This means that an explanation withregard to energy transfer for cyclotron resonance may be questionable,particularly for solid tissue.

It is also possible for the effect to be based on piezoelectricprocesses in the body. This explanation approach is based on theassumption that there is an electrical field around every body jointand, in the healthy state, every movement causes a piezo voltage, sincethe cartilage has piezoelectric characteristics. In the unhealthy state,these piezo voltages could be simulated by induced voltages. In thiscontext, see also Christian Thuile, “Das groβe Buch derMagnetfeldtherapie”, Linz 1997. [The Big Book on magnetic fieldtherapy].

A further apparatus for treatment of a biological body with magneticfields, which produces spin resonances within the body to be treated, isdisclosed in Laid-Open Specification WO 99/66986 from the sameapplicant. This apparatus as described in Laid-Open Specification WO99/66986 is, however, essentially based on carrying out specificreproducible treatment with magnetic fields in all biological materials,irrespective of whether any ionic parts are present. The citedapparatus. achieves the positive therapeutic effects by production ofspin resonances and spin resonance sequences. In this case, the nuclearmagnetic resonance is, however, also used in particular for energytransfer. In other fields of technology, nuclear magnetic resonancemethods (so-called NMR methods) have already been known for a long time.They are used in particular for medical diagnosis and in general for thehigh-precision magnetic field measurement. With regard to the latterapplication, reference should be made, for example, to the “VirginiaScientific FW101 Flowing Water NMR Teslameter”.

It should also be stated that the known apparatuses for therapeuticmedicine generally comprise large coil systems with which the magneticfields are generated and varied. However, these coil systems have a highinductance, which leads to long switching time constants and toconsumption of a large amount of energy. Long switching timesdisadvantageously lead, however, to poor efficiency with regard todynamic processes in the body.

Furthermore, the coil systems are typically designed such that they haveopenings into which body parts, for example, arms or legs, can beinserted. In consequence, the known apparatuses are relatively shapelessand have disadvantages with regard to the possible ways to store themand transport them. Apart from this, in some cases, they are notconvenient for the patient. Furthermore, the energy required for themost known apparatuses is very high, since the coil systems producestrong magnetic fields.

In addition, there are still a number of open questions with regard tothe physical-physiological way in which the apparatuses operate and withregard to the processes which are initiated by them in the body.However, in the past, without any detailed knowledge of the way in whichthey operate, an optimized design and the optimum parameters for itsoperation could be determined only with difficulty.

One object of the present invention is thus to provide an improvedapparatus and an improved method for treatment with magnetic fields.

A further object of the invention is to make an apparatus and a methodavailable by means of which electromagnetic stimuli which are producedby movement in the body, in particular the natural behavior of magneticmoments in the body can be modeled or simulated artificially duringmovement in the earth's magnetic field.

Another object of the invention is to make available an apparatus and amethod which allow short switching time constants and consume littleenergy.

A further object of the invention is to make available an apparatus fortreatment with magnetic fields, which can be transported and storedeasily, is convenient for the patient and, in particular, can also bemanufactured at low cost.

The invention is based on the extremely highly surprising knowledge thatpositive therapeutic effects from treatment with magnetic fields can betraced back to movement simulation via spin resonance signals.

Magnetic moments, for example electron and nuclear spin moments can bealigned just in the earth's magnetic field in a human, animal or otherbiological body, and thus produce macroscopic magnetization. Anymovement of a body part leads to a small change in the direction of thismagnetization. Provided that the magnetization direction is not alignedparallel to the earth's magnetic field direction, the magnetizationprecesses at a frequency of about 2000 Hz in the earth's magnetic field,and induces an alternating voltage at the same frequency in theenvironment. This induced voltage can be measured using an externalcoil, and is in the milli volt range. However, the induced voltage inthe body is considerably greater since the distances are shorter. Thehuman nervous system registers this voltage and thus identifies themovement. In consequence, the metabolism is activated since energy isrequired for muscular work.

Various debilitations restrict the movement of a patient and his or hermetabolism. The apparatus according to the invention and the methodresult in predetermined and deliberate rotation of the spins and of themacroscopic tissue magnetization that is produced by the spins. Withregard to the spin resonances which are produced naturally by theearth's magnetic field in the body, the organism is made to believe thatmovement has taken place, which has not taken place in reality. To dothis, the apparatus according to the invention produces suitablemagnetic fields which vary the alignment of the spins and/or of themagnetization in such a way that this simulates a movement of the bodyarea which is arranged in the treatment area. In this context, it hasbeen possible, inter alia, by the use of the present invention, toachieve very good treatment success in the therapy for osteoporosis.

A first embodiment of the invention is distinguished in that theapparatus according to the invention for treatment with magnetic fieldscomprises a first and a second device for production of a first and asecond magnetic field, respectively, and a mount, in particular a matfor body areas of a patient to be treated, or the entire patient, torest on and/or against. In this case, the mount, such as the mat definesan upper face and a lower face, between which the first and seconddevices for production of the first and second magnetic fields,respectively, are preferably arranged. This arrangement allows a verycompact, in particular very flat, configuration.

In addition to a mat in which the devices for production of the firstand second magnetic fields are arranged, a treatment couch or atreatment stool may also be used as the mount. In addition, systems arepossible which are placed on the patient, or on the tissue to betreated. By way of example, the mount may comprise a multi-wingedarrangement which can be placed around a body part, in particular thehead, of a patient and is placed against the head of a patient. Thisapparatus may, for example, comprise two or more wings whose sizes aresuch that they can be placed around both ears or around the jaw of apatient. In particular, with this form of mount, the first and seconddevices for production of the first and second magnetic fields,respectively, can also be integrated in two or more or all of the wings.

Furthermore, the mount may also be in the form of leggings, which can beplaced around the legs or arms, for example.

Amount which comprises a cover may also be advantageous for certainapplications. For the treatment of animals, for example, inter alia suchas horses, the cover can be placed over the animal for treatment.

The apparatus is characterized in that the mount comprises a treatmentcouch and/or a treatment stool and/or a multi-winged arrangement whichcan be placed around a body part, in particular the head, of a patient,and/or leggings and/or a cover.

As is clear from the above examples, there are accordingly no limits tothe shape and condition of the mount, which can be matched appropriatelyto the purpose.

The atomic nuclei in the patient's tissue define a spin resonancefrequency, or have such a frequency, in the magnetic fields. In thiscase, the resonant frequency is correlated to the field strength of themagnetic field. For example, the following equation applies to hydrogenatoms:F[kHz]=4.225×B[Gauss],where F is the nuclear magnetic resonance frequency in kilohertz, and Bis the magnetic field strength in gauss. For example, the nuclearmagnetic resonance frequency is 16.9 kHz for a magnetic field of 4gauss.

The second device is preferably designed to produce an alternatingfield. The two devices for production of the first and second magneticfields in this case form, in particular, a classical arrangement forproduction of nuclear magnetic resonance. In this case, the secondmagnetic field preferably oscillates at the spin resonance frequency,which is defined essentially by the nature of the particles, elements orchemical compounds in the body and by the strength of the first magneticfield. The spin resonance frequency that is produced is preferablybetween 1 kHz and 1 MHz, particularly preferably between 2 kHz and 200kHz, and most preferably in the region of about 100 kHz.

A preferred embodiment in which the first and second devices arearranged in a plane which runs parallel to the plane of the mat isparticularly advantageous. In this case, the first and/or second devicescan preferably be arranged completely within the mat, between its upperface and lower face. This results in a particularly simple and practicalembodiment, in which the patient simply lies on the mat for treatment.This arrangement in a plane also provides a planar geometry, in whichmutually orthogonal magnetic fields can nevertheless be produced in thetreatment area.

The apparatus can be stored and transported particularly easily if,according to one preferred embodiment, the mat can be folded once ormore by subdivision into two or more sections. In this case, the firstand second devices are preferably accommodated in the same section ofthe mat. The mat preferably has a thickness of about 3 to 10 cm, a widthof 70 cm and a length of 210 cm, so that, when it is folded twice by wayof example, dimensions of about 9 to 30 cm by 70 cm by 70 cm areachieved.

The second device preferably comprises a toroidal coil. This defines acoil plane in which the windings run, and a coil axis which is at rightangles to the coil plane. As will be obvious to those skilled in theart, a magnetic field in the direction of the coil axis is essentiallyproduced in the center of the coil. In the direction of the coil axis,the coil or second device has an extent of less than 50 cm, preferablyof less than 20 cm, and particularly preferably of less than 10 cm, andmost preferably of between about 2 cm and 6 cm. The coil or seconddevice has a round to oval or elongated shape with semicircular endareas in the coil plane. In particular, the extent of the coil in thedirection of the coil axis is preferably less than the extent of thecoil plane, being less than it at least by a factor of 2 or particularlypreferably by at least a factor of 5. The special shape makes itpossible, in particular, for it to be accommodated completely in theflat mat by producing a highly effective magnetic field at the sametime, which is generally not possible with the known large coilarrangements.

The first device preferably comprises at least one, two, three orparticularly preferably four coils, with each of these coils preferablybeing combined with a fixed magnet, for example composed of a ferritematerial. This advantageously results in the production of a strongconstant basic magnetic field through the ferrite material, with anadditional magnetic field which varies with time being superimposed onit, produced by the coils.

It is thus possible to work with relatively small coils and littleenergy consumption, with an effective magnetic field at the same time.

In one preferred development, the first and second devices for producingthe first and second magnetic field, respectively, are arranged in aplane which runs parallel to the plane of the mat surface and the coilplane of the second device. If the first device has two or more coilsand/or fixed magnets, the second device is preferably arranged centrallybetween them.

In particular, the treatment field comprises at least onesuperimposition of the first and second magnetic fields. In thetreatment area above the mat surface, in particular where a patient islocated or is lying for treatment, the magnetic lines of force which areproduced by the first device run essentially parallel or at least at anacute angle in the range from 0° to 300 or from 0° to 45°, to the matsurface, and/or at right angles or at least at an obtuse angle in therange from 45° or 60° to 120° or 135° to the magnetic lines of force ofthe second device. The second magnetic field preferably runs at an anglein the range from 30° to 150°, particularly preferably in the range from45° to 135°, and particularly preferably in the range from 60° to 120°,and most preferably essentially at right angles to the mat surface.

In one embodiment of the invention, the treatment field can be variedwith time such that the alignment of the spins or of the macroscopicmagnetization which is produced by the spins can be varied by means ofthe variation of the treatment field with time so as to make it possibleto simulate a movement of the body area that is arranged in thetreatment area, in the earth's magnetic field.

The first magnetic field preferably comprises an essentially parallelsuperimposition, or parallel superimposition in other directions, of apreferably constant third magnetic field, which is preferably producedby the fixed magnets or ferrites, and of a fourth magnetic field, whichpreferably varies with time and is preferably produced by auxiliarycoils associated with the fixed magnets. In this case, the strength ofthe third magnetic field is preferably 0.5 gauss to 500 gauss,preferably from 10 gauss to 50 gauss, and particularly preferably in therange from 23 gauss to 24 gauss. The fourth magnetic field, which mayalso be referred to as the modulation field, oscillates periodically andpreferably regularly between preferably −10 gauss and +10 gauss,preferably between −1 gauss and +1 gauss, and particularly preferablybetween −0.5 gauss and +0.5 gauss, with the latter correspondingapproximately to the strength of the earth's magnetic field. It isobvious to those skilled in the art that the third magnetic fieldrepresents a constant basic field, and the fourth magnetic fieldrepresents amplitude modulation of the first magnetic field.

The fourth magnetic field preferably describes a triangular or sawtooth,waveform oscillation which is symmetrical about 0 gauss, so that thefirst magnetic field oscillates about the value of the third magneticfield or constant basic field. In consequence, the first magnetic fieldis preferably amplitude-modulated with a triangular waveform. Themathematical resonance condition is in this case satisfied precisely atthe point at which the fourth magnetic field disappears. The strength ofthe third magnetic field is in this case at least 4 times, 10 times or20 times as great as the maximum strength of the fourth magnetic field.

If the second magnetic field, as an alternating field and at a frequencywhich corresponds to the spin resonance frequency of the particles inthe tissue in the third magnetic field, is now injected essentially atright angles to the first magnetic field, then this corresponds to anarrangement for producing a so-called fast adiabatic run.

The second magnetic field or alternating field preferably has differentintensities during the rising and falling flanks of the first magneticfield. The second magnetic field is particularly preferably injectedduring the falling flank of the first magnetic field, and is switchedoff during the falling flank, or vice versa. As a consequence, the spinsor the macroscopic magnetization during the “on time” of the secondmagnetic field are rotated adiabatically away from the direction of thebasic field, and relax back again during the “off time” of the secondmagnetic field.

The frequency of the fourth magnetic field or of the amplitudemodulation of the first magnetic field is thus preferably matched to thespin lattice relaxation time of the particles in the tissue. This leadsto a preferred period duration of the modulation of the first magneticfield of 1 ms to 10 s, preferably 10 ms to 1 s, and particularlypreferably in the region of 200 ms.

As an alternative to the arrangement for a fast adiabatic run, thesecond magnetic field or alternating field is injected in a short pulse,for example a so-called 90 pulse or a 180° pulse.

The invention will be explained in more detail in the following textusing preferred embodiments and with reference to the drawings.

BRIEF DESCRIPTION OF THE FIGURES

In the figures:

FIG. 1 a shows a view of a first embodiment of the invention with thedimensions in mm,

FIG. 1 b shows a section drawing along the section line A-A in FIG. 1 awith the dimensions in mm,

FIG. 2 shows a time profile of a magnetic field B(t) and of theresultant macroscopic magnetization M(t),

FIG. 3 shows an illustration of the alignment of macroscopicmagnetization M in a constant magnetic field B₀,

FIG. 4 shows a time profile of a magnetic field B(t) and of theresultant magnetization components M_(z)(t) and M_(xy) (t) when a 90°pulse is injected,

FIG. 5 shows an oscilloscope print-out of a nuclear magnetic resonancesignal with phase-sensitive detection using a 100 kHz reference,

FIG. 6 shows a time detail of a nuclear magnetic resonance signal forB₀=23.4 gauss,

FIG. 7 shows a time detail of a nuclear magnetic resonance signal forB₀=23.2 gauss,

FIG. 8 shows a time detail of a nuclear magnetic resonance signal forB₀=23.8 gauss,

FIG. 9 shows a profile of the magnetic field strength as a function ofthe relative frequency,

FIG. 10 a shows a schematic illustration of the spatial alignment ofmagnetic fields for a fast adiabatic run at the time t₀,

FIG. 10 b is as FIG. 10 a, but for the time t₁ instead of t₀,

FIG. 10 c is as FIG. 10 a, but for the time t₂ instead of t₀,

FIG. 11 shows a schematic illustration of the time profile of the firstand second magnetic field, and

FIG. 12 shows a block diagram of the apparatus according to theinvention with control electronics.

FIG. 13 a shows a view of a second embodiment of the invention,

FIG. 13 b shows a section drawing along the section line A-A in FIG. 13a, and

FIG. 14 shows a block diagram of a circuit for controlling the coil inthe second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Nuclear magnetic resonance makes it possible to vary the magnetizationdirection in the body without the body being in motion in the process,since the induced nuclear magnetic resonance voltage simulates thebody's own movement process. The apparatus and the method according tothe invention can thus be used to carry out a therapy which stimulatesor speeds up the metabolism.

FIGS. 1 a and 1 b show a first embodiment of the invention, in which theillustrated dimensions shall be regarded as being only by way ofexample. The apparatus 1 according to the invention comprises a mat 10which is subdivided into three sections and can be folded, of which onlythe central section 12 is illustrated, extending in the plane of thedrawing. A second device, at right angles to the plane of the drawingand in the form of a flat toroidal coil 14, is embedded in the section12 of the mat 10 in order to produce a second magnetic field incushioning 16 composed of a flexible material, for a example a foammaterial. The toroidal coil or transmission coil 14 extends in the planeof the drawing with a width of about B=350 mm and a height of aboutH=550 mm, with the head ends 14 a, 14 b each being designed to besemicircular. The length of the coil at right angles to the plane of thedrawing is about L=52 mm. The cross section through the coils is definedby the length L and a cross-sectional width of about QB=75 mm. Thethickness of the mat is about D=132 mm, with the toroidal coil beingarranged centrally in the mat, so that cushioning 16, which is alsoabout 40 mm, is in each case arranged between the mat upper face andlower face. There are two devices 22, 24, 26, 28 in each case to theleft and to the right of the coil in order to produce a first magneticfield, and these each comprise a fixed magnet 32, 34, 36, 38 and anauxiliary coil 42, 44, 46, 48 in each case, which surround the fixedmagnets in the mat plane. Each device 22, 24, 26, 28 has a height ofabout 200 mm, a width of about 100 mm and a length L at right angles tothe plane of the drawing of about 52 mm. The devices 22, 24, 26, 28 areeach separated by about 50 mm from the toroidal coil 14 in the directionof the width, and two of the devices 22 and 24 as well as 26 and 28 arein each case adjacent to one another in the vertical direction.

90° Nuclear Magnetic Resonance Signal Pulsed Method

As has already been stated above, a first embodiment of the inventionuses a pulsed method, which will be described in detail in the followingtext.

The molecules or macromolecule complexes of our body are made uppredominantly of hydrogen atoms, for example in water (H₂O) or inorganic molecules (for example in CH₂ or CH₃). The cores or ions of thehydrogen are protons. Protons have a magnetic moment and a spin(obviously a torque) with a ratio γ (gyromagnetic factor) between them.For protons, γ=2.67522 10⁸T⁻¹s⁻¹. A steady-state magnetic field B₀, forexample the earth's magnetic field, produces macroscopic magnetizationM(t) exponentially over time with a time constant T₁. This is definedby:M(t)=M ₀(1−e ^(−t/T1))whereM₀=χB₀where T₁ is the spin lattice relaxation time and M₀ is the asymptoticvalue of the magnetization. The time profile of the magnetization M(t)which is produced by a sudden application of a magnetic field B₀ whichis constant after the rise is illustrated in FIG. 2. For protons orhydrogen in human tissue:T₁=10s . . . 10⁻³s.

A spin echo measurement is preferably carried out before the therapeutictreatment, in order to determine the spin lattice relaxation time.

The macroscopic magnetization M is aligned asymptotically parallel toapplied magnetic field B=B₀, as is illustrated in FIG. 3. FIG. 3 alsoshows a rectangular and right-handed coordinate system XYZ, which isused as the basis of the orientation for the following analysis.

Microscopically and as required by quantum mechanics, all of the protonspins carry out a precession movement about B₀ at a frequency f₀. Thisfrequency is referred to as the Larmor frequency. The Larmor frequencyf₀ is determined as follows:

$f_{0} = {\frac{\omega_{0}}{2\pi}.}$

From this, in the earth's magnetic field, that is to say for B₀=0.5Gauss=5 10⁻⁵T

$f_{0} = {\frac{\gamma\; B_{0}}{2\pi} = {{\frac{2\text{,}{67522 \cdot 10^{8} \cdot 5 \cdot 10^{- 5}}}{2\pi}\mspace{14mu}{Hz}} = {2128\text{,}872\mspace{14mu}{Hz}}}}$

In the earth's magnetic field, the Larmor frequency for protons is inconsequence about 2 kHz. The Larmor frequency is also varied only veryslightly by the chemical bonds.

FIG. 5 shows an oscilloscope print-out for experimental verification ofthe Larmor frequency by means of a spin echo measurement with 500 ml ofwater at 100 kHz and using a 23.5 gauss spectrometer. A 90° pulse and a180° pulse are injected, and the spin echo is detected. FIGS. 6 to 8show the spin echoes for a first magnetic field B=23.2 gauss, 23.4 gaussand 23.8 gauss on an enlarged time scale. The first magnetic field B isproduced by parallel superimposition of a constant magnetic field B₀, bymeans of the four fixed magnets which are in the form of ferrite magnets32, 34, 36, 38, and of a magnetic field ΔB₀, which varies with time,produced by the four auxiliary coils 42, 44, 46, 48.

FIG. 9 illustrates the three measurement points from FIGS. 6 to 8 in theform of a graph of the magnetic field in gauss as a function of therelative frequency in Hz. The straight line is a linear interpolationthrough the measurement points. The relative frequency represents thefrequency error from the resonant frequency f₀, which is defined by thebasic field B₀=23.5 gauss.

The apparatus according to the invention comprises a flat coil ortransmission coil 14 for producing the second magnetic field in the formof a magnetic alternating field B₁ at a frequency f_(o) of about 100kHz. This frequency corresponds approximately to the Larmor frequency ofprotons in a mean magnetic field of B=23.5 gauss.

For this purpose, the transmission coil 14 is preferably connected in avery simple manner to a capacitor in order to form a resonant circuit.The resonant frequency of the resonant circuit f_(LC) is

${f_{LC} = \frac{1}{2\pi\sqrt{LC}}},$where L is the inductance of the transmission coil 14, and C is thecapacitance of the capacitor.

If the body areas of a patient or of biological tissue are located inthe first magnetic field B, which initially has a constant strength ofB₀=23.5 gauss, the macroscopic magnetization M of the tissue is thevector sum of the nuclear spins parallel to B₀, when B₀ in thisembodiment runs parallel to the Z-axis (see FIG. 3).

A nuclear magnetic resonance method is now used to deflect themagnetization M away from the B₀ direction. Nuclear magnetic resonancechanges the magnetization direction, even though the body is at rest.The induced voltage produces an effect as if the body were in motion.Nuclear magnetic resonance can then be used to carry out therapy bystimulating the metabolism.

A so-called 90° radio-frequency pulse is used to rotate themagnetization through 90°. The time profile of the magnetic field and ofthe magnetization components M_(z)(t) and M_(xy)(t) is shownschematically in FIG. 4. The transmission coil, whose axis runs parallelto the X axis, generates a rotating radio-frequency field B₁, or onewhich oscillates linearly in the X direction. The macroscopicmagnetization M rotates at a frequency f₁ about the X axis from thepositive Z direction to the X-Y plane. In this case:f ₁=ω₁/2πwhereω₁=γB₁

The angle α through which M rotates is:α=ω₁t.

For a 90° rotation, that is to say α=π/2, the time duration of the 90°pulse t₉₀ is calculated to be:

$t_{90} = {\frac{\pi}{2}{\frac{1}{\gamma\; B_{1}}.}}$

The macroscopic magnetization M is in the direction Y after injection ofthe 90° pulse. It rotates at ω₀ about the Z axis and induces a voltagein the radio-frequency coil, which can be measured as a nuclear magneticresonance signal. This signal decays exponentially with the timeconstant T₂*, and:M _(xy) =M ₀ ·e ^(−t/T2*)

-   For a homogeneous magnetic field B: T₂*≅T₂,-   where T₂ is the spin-spin relaxation time.-   For a less homogeneous magnetic field B: T₂*<T₂-   For liquids: T₁≅T₂-   Typical values for T₂ are:-   Tap water: T₂≅3s-   Distilled water: T₂≅30 s to 3 min-   Human tissue: T₂≅10 ms to 1 s-   Tissue of a hand: T₂≅100 ms to 1 s.    Fast Adiabatic Nuclear Magnetic Resonance Run

With reference to FIGS. 10 a to 10 c and, alternatively, the pulsedmethod described above, specific rotation of the magnetization isachieved by means of a fast adiabatic run, which is described in thefollowing text. This is achieved by a field variation of the firstmagnetic field B or a frequency variation of the alternating field B₁,in which case the magnetization M can be rotated from 0 to 180° withrespect to the Z axis.

The following magnetic fields are defined in a coordinate system (X′ Y′Z) which rotates at ω₀ about the Z axis:ΔB ₀ =B−B ₀ where B ₀=ω₀/γ

-   -   B₁ and    -   B_(R).

In this case, B₁ is an alternating field or radio-frequency field whichis produced by the transmission coil 14 and, at the time t=t₀, runsparallel to the X′ axis in the coordinate system X′Y′Z. B_(R) is themagnetic field or treatment field which results from the superimpositionof B and B₁.

FIG. 10 a shows the alignment of the magnetic field vectors in space atan instant relating to the time t₀. The illustration shows the vector ofthe fourth magnetic field ΔB₀, produced by the auxiliary coils 42, 44,46, 48, and which runs parallel to the Z axis. In this case, ΔB₀ is thepositive or negative excess of the magnetic field B above or below theresonant third magnetic field B₀, respectively, which is produced by theferrite magnets 32, 44, 46, 48, points in the positive Z direction allthe time, and is not illustrated in FIGS. 10 a to 10 c.

If only the magnetic field B(t)=B₀ acts initially, then the macroscopicmagnetization of the tissue is aligned in the direction of the Z axisand the individual spins precess at the angular frequency ω₀ about the Zaxis. This means that the spins are initially stationary with respect tothe rotating coordinate system X′Y′Z.

The third magnetic field ΔB₀ and the alternating field B₁, which aresuperimposed to form the resultant magnetic field B_(R), are nowincreased until the time t=t₀. The vector of the alternating fieldB₁(t₀) points in the direction of the X′ axis.

The alternating field B₁ oscillates linearly at the frequency ω₀essentially at right angles to the Z axis. Alternatively, the field B₁may also rotate at the frequency ω₀ about the Z axis. This is equivalentin terms of the projection in the X′-Z plane. Since the nucleus spinsalso rotate about the Z axis at the same frequency ω₀, they are alwaysin phase with the alternating field B₁.

Based on a classical interpretation, a resultant force F always acts onthe magnetization or the spins in this arrangement, with this force Frotating the magnetization M or the spins in the X′-Z plane away fromthe Z axis. During this rotation, the spins essentially precess inphase. This rotation reduces the fourth magnetic field or modulationfield ΔB₀ to zero and then increases it further again continuously inthe negative Z direction, in order to follow the change in themagnetization direction. This makes it possible to rotate themagnetization into the direction of the negative Z axis, that is to sayto rotate the magnetization of the nuclei through 180°.

FIG. 10 b shows the alignment of the magnetization M and of the variousmagnetic fields at a time t₁, which occurs later than t₀. Themagnetization vector M has already been rotated to a considerable extentaway from the Z axis.

In a corresponding manner, FIG. 10 c shows an instant relating to a timet₂ which occurs even later than t₁.

In order to maximize the desired effect of motion simulation, themagnetization M should be rotated as frequently as possible. For thispurpose, the auxiliary coil which produces the magnetic field ΔB₀ ismoved in a triangular shape, in a sawtooth shape or in a sinusoidalshape between ΔB₀ ^(max) and −ΔB₀ ^(max), that is to say symmetricallyaround zero. At the top, FIG. 11 shows schematically the most preferredtriangular-waveform modulation of the first magnetic field B(t). Thetimes t₀, t₁ and t₂ from FIGS. 10 a to 10 c are also shown. When themagnetic field B(t) is falling, the transmission coil and thealternating field B₁ are switched on in order to rotate themagnetization away from the positive Z axis, while the transmission coilis switched off when the field rises. In consequence, the alternatingfield B₁(t) is amplitude-modulated with a square-waveform according tothis exemplary embodiment. Other modulation forms for the first and/orsecond magnetic field, for example sinusoidal amplitude modulation, are,however, likewise within the scope of the invention. The blocks 50 whichare shown at the bottom of FIG. 11 represent, schematically, the on-timeof the alternating field B₁. During the off-time of the alternatingfield B₁, the spins relax, and the magnetization decreases again. Themodulation period of the first and the fourth magnetic field is thusmatched to the spin lattice relaxation time of the tissue, or at leastcorresponds to its order of magnitude. The period of the variation ofthe first magnetic field with time is preferably from one tenth to 10times, in particular from once to 3 times or 5 times, the spin latticerelaxation time.

It is also within the scope of the invention for the falling flank ofthe modulation field ΔB₀ to be made to be steeper than the rising flank,in order to achieve faster rotation.

The adiabatic run has been explained above by means of modulation of thefirst magnetic field B(t). The run can also be carried out analogouslywith a constant first magnetic field B=B₀ and a corresponding frequencychange (so-called frequency sweep) of the alternating field B₁.

In addition, a receiving coil whose axis is in the Y direction detectsthe induced nuclear magnetic resonance signal, and is sensitive to itsphase. The time integral of this signal is proportional to the totalnuclear magnetic resonance effect, and is thus maximized.

One advantage of the adiabatic run is that the first magnetic field Bmay have up to about 10% inhomogeneity. This means that the method isseveral orders of magnitude less sensitive in this context than knownmethods, such as the spin echo method. The invention is alsocorrespondingly insensitive to the angle between the first and secondmagnetic fields.

FIG. 12 shows an example of a circuit arrangement for the apparatusaccording to the invention, it respectively having an amplifier 52 and54 for driving the transmission coil 14 and the auxiliary coils 42, 44,46, 48. A control device or control logic 56 is associated with thetransmission coil 14 and with the auxiliary coils 42, 44, 46, 48, aswell as with the two amplifiers 52 and 54, and controls the modulationof the first and second magnetic fields.

FIGS. 13 a and 13 b show a second embodiment of the invention. In thiscase, FIG. 13 a shows a view of this second embodiment and FIG. 13 bshows a section drawing along the section line A-A in FIG. 13 a. The mat10 has a flat toroidal coil 15 in whose inner area 151 two further flattoroidal coils 17 and 19 are arranged. In the same way as the embodimentwhich has been described with reference to FIGS. 1 a and 1 b, thisembodiment is also suitable, for example, for implementing the 90°nuclear magnetic resonance signal pulsed method and the fast adiabaticnuclear magnetic resonance run.

The toroidal coil 15 produces a quasi-static magnetic fieldB(t)=B₀+ΔB₀(t). In order to achieve a wide treatment range, themagnitude of ΔB₀(t) is preferably half as much as B₀.

The flat toroidal coils 17 and 19 are operated in opposite senses, sothat a north pole and a south pole respectively of the two coils pointtoward one face of the mat 10. In this way, these coils produce amagnetic field B₁ which, in the areas 21 and 23 above and below the mat10, is essentially at right angles to the magnetic field B which isproduced by the toroidal coil 15. When a patient is lying on the mat,then the tissue of the patient is located within this area 21. The area21 thus defines a treatment area for the tissue to be treated.

The time profile of the magnetic field B(t) and of the magnetic field B₁is in this case controlled as has been described above with reference tothe further embodiments.

In contrast to the first embodiment of the invention, the magnetic fieldB in the treatment area runs approximately at right angles to the matsurface, however, or at right angles to the magnetic field B(t) producedby the coils 22, 24, 26, and 28 in the first embodiment. Furthermore, nofixed magnets are required for the second embodiment. The constantmagnetic field component B₀ can in fact be produced by suitableoperation of the toroidal coil 15, in the same way as the magnetic fieldΔB₀ which varies with time.

FIG. 14 shows, in the form of a block diagram, suitable control for thecoils 15, 17 and 19 for producing a quasi-static magnetic field B(t), aswell as an alternating field B₁(t) with a time profile as illustrated,by way of example, in FIG. 11. In a similar way to the controlillustrated in FIG. 12, the control has a logic circuit 56. The logiccircuit 56 drives an amplifier 58 for driving the toroidal coil 15, aswell as an amplifier for driving the toroidal coils 17 and 19 in orderto produce the alternating field B₁. The amplifier 58 in this caseproduces a constant current for an embodiment without permanent magnets,which produces a constant magnetic field B₀ in the coil 15, as well as acurrent which is applied thereto, varies with time, and produces thevariable magnetic field component ΔB₀.

In summary, the present invention proposes a magnetic field therapyapparatus and a magnetic field therapy method which use the nuclearmagnetic resonance signal as a motion sensor in order to stimulate themetabolism. The signal in this case simulates the motion of a body part.One advantageous feature in this case is that the proposed nuclearmagnetic resonance therapy in all probability has no negative effects onthe organism.

The nuclear magnetic resonance therapy apparatus according to theinvention allows the magnetization to be rotated quickly and usinglittle energy. The rotation is carried out, in particular, within onemicrosecond up to 30 seconds.

1. An apparatus for treatment with magnetic fields, comprising: a firstdevice for production of a first magnetic field, a second device forproduction of a second alternating magnetic field, with the first deviceand the second device forming an arrangement for production of nuclearmagnetic resonance, wherein the second magnetic field runs essentiallyat right angles to the first magnetic field, and a mount with an upperface and a lower face, the mount being designed to be placed on bodyareas of a patient to be treated, wherein said second device comprises acoil having a coil axis that is disposed essentially at right angles toa surface of said mount, wherein said first device for production ofsaid first magnetic field comprises at least two further coils beingarranged adjacent to said coil of said second device for production ofsaid second magnetic field, and wherein the first and second devices arearranged in a first plane, the upper face of the mount extends in afunctional state essentially in a second plane, and the first plane runsessentially parallel to the second plane.
 2. The apparatus as claimed inclaim 1, wherein, in a treatment area above the upper face of the mount,the first magnetic field is disposed at an acute angle with respect tothe upper face or the second magnetic field is disposed at an obtuseangle with respect to the upper face.
 3. The apparatus as claimed inclaim 1, wherein elements or compounds which are contained in the bodyareas to be treated have at least one spin resonance frequency in thefirst magnetic field, and the second magnetic field oscillates at leastat times at a frequency which corresponds to the spin resonancefrequency.
 4. The apparatus as claimed in claim 1, wherein the firstdevice comprises two or four coils between which the second device issubstantially disposed.
 5. The apparatus as claimed in claim 1, whereinthe mount comprises a filling in which the first or second device isembedded.
 6. The apparatus as claimed in claim 1, comprising a cushionedcasing with an opening, which can be closed, for introduction or removalof the first or second device.
 7. The apparatus as claimed in claim 1,wherein the mount is subdivided into a plurality of sections, and themount can be folded between the plurality of sections.
 8. The apparatusas claimed in claim 1, wherein the first device is designed to produce amagnetic field which varies with time.
 9. The apparatus as claimed inclaim 1, wherein the first device comprises at least one fixed magnetand at least one coil.
 10. The apparatus as claimed in claim 1, whereinintensity or direction of the first magnetic field can be varied. 11.The apparatus as claimed in claim 1, wherein the mount is chosen fromthe group consisting essentially of a mat, a treatment couch, atreatment stool, a multi-winged arrangement which can be placed around abody part of a patient, leggings, a cover, and any combinations thereof.